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From Andrey Ilinykh <ailin...@gmail.com>
Subject Re: How often to run `nodetool repair`
Date Thu, 01 Aug 2013 20:16:15 GMT
On Thu, Aug 1, 2013 at 12:26 PM, Robert Coli <rcoli@eventbrite.com> wrote:

> On Thu, Aug 1, 2013 at 9:35 AM, Carl Lerche <me@carllerche.com> wrote:
>
>> I read in the docs that `nodetool repair` should be regularly run unless
>> no delete is ever performed. In my app, I never delete, but I heavily use
>> the ttl feature. Should repair still be run regularly? Also, does repair
>> take less time if it is run regularly? If not, is there a way to
>> incrementally run it? It seems that when I do run repair, it takes a long
>> time and causes high amounts CPU usage and iowait.
>>
>
> TTL is effectively DELETE; you need to run a repair once every
> gc_grace_seconds. If you don't, data might un-delete itself.
>

How is it possible? Every replica has TTL, so it when it expires every
replica has tombstone. I don't see how you can get data with no tombstone.
What do I miss?

Andrey

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